We really need a set of current water testing results taken with a drops-based kit. What kind of "shock" have you been using -- meaning ingredients. How much stabilizer did you add, how did you add it, and when? Do you have any idea what your stabilizer (CYA) level was when you closed the pool? What did you use for chlorine last year?

You'll need a good test kit if you don't already have one. The one we recommend is the Taylor K-2006 or 2006C (same kit, larger bottle of some reagents). If you buy it through the Amazon link in my signature, the Pool Forum makes a little money on the sale which helps us keep this form online. Only buy if the seller is Amato Industries, however. Some other sellers are substituting the K-2005 which you do NOT want.

Repost with requested info and somebody here can try and help you. Welcome to the Pool Forum!